How to unwrap single item array and extract value field into one simple field?

Question

I have a JSON document similar to the following:

{
  \"aaa\": [
    {
      \"value\": \"wewfewfew\"
    }
  ],
  \"bbb\": [
    {
      \"value\": \"wefwefw\"
          


        

Answer 1

Quick solution with Gson is to use a JsonDeserializer like this:

package stackoverflow.questions.q17853533;

import java.lang.reflect.Type;

import com.google.gson.*;

public class MyEntityDeserializer implements JsonDeserializer {
    public MyEntity deserialize(JsonElement json, Type typeOfT,
        JsonDeserializationContext context) throws JsonParseException {

    String aaa = json.getAsJsonObject().getAsJsonArray("aaa").get(0)
        .getAsJsonObject().get("value").getAsString();
    String bbb = json.getAsJsonObject().getAsJsonArray("bbb").get(0)
        .getAsJsonObject().get("value").getAsString();

    return new MyEntity(aaa, bbb);
    }
}

and then use it when parsing:

package stackoverflow.questions.q17853533;

import com.google.gson.*;

public class Q17853533 {


  public static void main(String[] arg) {
    GsonBuilder builder = new GsonBuilder();
    builder.registerTypeAdapter(MyEntity.class, new MyEntityDeserializer());

    String testString = "{        \"aaa\": [{\"value\": \"wewfewfew\"  } ],  \"bbb\": [  {\"value\": \"wefwefw\" } ]    }";


    Gson gson = builder.create();
    MyEntity entity= gson.fromJson(testString, MyEntity.class);
    System.out.println(entity);
  }

}